“Monkeybone” is a fairly bad movie in a good movie’s clothing.

It was directed by Henry Selick, who also helmed “The Nightmare Before Christmas,” and the look and feel are the same: dark, visually entertaining, and sometimes just flat-out weird. There are hallucinatory images that are nearly nightmarish, and the mixing of real actors, computer animation and puppets is impressive.

What it lacks is a good script. Unsure whether it’s a comedy or a big-screen comic book, “Monkeybone” dabbles in both and does neither one very well.

Stu Miley (Brendan Fraser) is a cartoonist whose strip, “Monkeybone,” is about to be turned into a TV show. All the money and merchandising are coming with it, but Stu is more interested in proposing to his girlfriend, Julie (Bridget Fonda).

On the way home from the premiere screening, Stu wrecks the car and goes into a coma. While Julie keeps a vigil (and Stu’s heartless sister plans to pull the plug), Stu’s soul is sent to Downtown, a hellish carnival land whose denizens watch other people’s nightmares for entertainment, and where the bar’s lounge act is … Monkeybone.

Monkeybone (voice of John Turturro) is Stu’s repressed Id, in the form of a cartoon monkey. He’s brash and loud and oversexed — all the things Stu normally is not. Stu would just as soon keep Monkeybone repressed, but instead the two of them must work together to steal an “exit pass” and get back to the land of the living.

To do this, they encounter Death herself (Whoopi Goldberg), but Monkeybone double-crosses Stu. He leaves Stu in Downtown, and himself goes back into Stu’s body. Julia wonders why Stu is suddenly so wacky, but what are you gonna do?

The real Stu has to find another body, meanwhile, and this leads to the film’s best sequence. Chris Kattan plays a newly deceased organ donor whom Stu briefly inhabits, and it’s hilarious. Kattan makes for a surprisingly good Brendan Fraser double, at least in voice and manner, and that climactic scene is very enjoyable.

Everything else, well, no so much. The humor is scattershot and the characters non-existent. It’s downright boring sometimes.

Oddly, though the special effects are seamless, much of the regular filmmaking is sloppy. Stu’s hands and face are covered with frosting in one shot, clean the next, and sort-of messy in the next. It’s daylight as Stu enters a building, dark when he briefly leaves, and light again when he comes out for good later. Perhaps Selick was so intent on getting the crazy stuff right, he neglected to look at the mundane things, like continuity and a good script.

C+ (; PG-13, some profanity, partial nudity, some violence.)